Feeding mechanism for sewing machines



Oct. 25, 1932. c. s, THOMPSON ET AL FEEDING MECHANISM FOR SEWING MACHINES Filed Nov. 6, 1926 4 Sheets-Sheet l Oct. 25, 1932.

' C. S. THOMPSON ET AL FEEDING MECHANISM FOR SEWING MACHINES Filed Nov. 6, 1926 4 Sheets-Sheet 2 f,Oc t.25, 1932. c. s. THOMPSON ET AL FEEDING MECHANISM FOR SEWING MACHINES Filed Nov. 6, 1926 4 Sheets-Sheet 5 3 c. s. THOMPSON'ET AL 1,884,383

I FEEDING MECHANISM FOR SEWING MACHINES Filed Nov. 6., 1926 4 Sheets-Sheet 4 36 gz I Fetented Got. 25, 1932 .QFFECE.

CHARLES S. THOMPSON, OF PARK RIDGE, AND WILLIAllrI B. LONG, OF CHICAGO, ILLINOIS, ASSIGNORS T UNION SPECIAL MACHINE COMIANY, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS FEEDING MECHANISM FOR SEWING MACHINES Application filed. November 6,

The invention relates to new and useful improvements in feeding mechanisms for sewing machines, and more particularly to a differential feeding mechanism for a multiple needle machine.

An object of the invention is to provide a feeding mechanism of the above type wherein the main feed dog is adjustable vertically and also laterally of the feed bar on which it is supported.

A further object of the invention is to provide a sewing machine of the above type wherein the auxiliary feed dog is adjustable both vertically and longitudinally of the feed bar on which it is mounted.

Another object of the invention resides in providing feeding mechanism of the above type wherein the working posit on of both feed dogs may be simultaneously shifted.

A. further object of the invention is to provide means whereby the guiding bars for the auxiliary feed bar on the main feed bar may be adjusted for taking up wear of the parts.

A further ob'ect of the invention is to provide a mach ne of the above type wherein the feed bar supporting the auxiliary feed dog is mounted so as to slide back and forth on the feed bar carrying the main feed dog, and wherein means is provided for varying the relative throw of the auxiliary feed dog and the main feed dog in such a way that the change in the length of stroke of the auxiliary feed dog is obtained at the forward end of the stroke and the extreme rear movement of the auxiliary feed dog is the same for all adjustments.

A further obi ect of the invention is to provide a. feeding mechanism of the above type wherein the auxiliary feed dog is spaced from the main feed dog and so supported as to provide ample clearance space between the feed dogs for the operation of the members, and for the positioning of a gu de for directa lining strip upwardly from beneath the work support between the feel dogs and through the work support and underneath the p'resser foot.

These and other objects will in part be obvious and will in part be hereinafter more fully described.

1926. Serial No. 146,715.

In the drawings which show by way of illustration'one embodiment of the invention:

Figure 1 is a view partly in front elevation and partly in vertical section showing a sewing machine embodying the improvements.

Fig. 10 is a longitudinal section through the throat plate showing the spacing of the auxiliary feed dog from the main feed dog, and the manner of directing a lining strip between the feed dogs.

Fig. 2 is a view partly in plan and partly in section of the parts immediately beneath the work support.

Fig. 3 is a vertical sectional view on the line 3-3 of Fig. 2.

Fig. l is a horizontal sectional view on the line l-4 of Fig. 3.

Fig. 5 is a plan view of the front end portions of the feed bar and showing in section the support for the main feed dog.

Fig. 6 is a perspective View of the supporting bracket for the auxiliary feed dog.

Fig. 7 is a sectional view on the line 7'7 of'Fig. 4c.

Fig. 8 is a sectional view on the line 8-8 of Fig. 2.

Fig. 9' is a sectional view on the line 9-9 of Fig. 2.

Fig. 10 is a sectional View onthe line 10- 10 of Fig. 9.

The invention is directed to a feeding mechanism for sewing machines and more particularly to a differential feeding mechanism used in connection with a multiple needle machine.

As illustrated, the invention is particularly adapted for applyin facing strips to knitted underwear, and to this end a differential feeding mechanism is utilized wherein the auxiliary feed dog is spaced from the main feed dog sufficiently to permit the lining strip to be fed from beneath the work support between the two feed dogs and up'through the work support and thence beneath the presser foot.

In a machine of this type it is very desirable to have a durable supporting means for the feed dogs and a supporting means for the feed dogs which permits of the adjustment of the dogs so as to properly position the same relative to the feed slots and also relative to the guide for the lining strip. The auxiliary feed bar is supported by the main feed bar and moves back and forth thereon, and means is provided for taking up the wear of the parts so that said auxiliary feed bar Will always be supported so as to provide a rigid support for the auxiliary feed dog which is located in front of the loopers, and also in front of the guide beneath the work support.

The auxiliary feed dog is mounted on a bracket so that it may be adjusted vertically and the bracket is mounted on the auxiliary feed bar so that it may be adjusted longitudinally of the feed bar. This enables a proper positioning of the auxiliary feed dog relative to the parts adjacent the same. The main feed dog is mounted on the main teed bar so that it may be raised and lowered, and so that it may be shifted laterally to bring the scctions of the main feed dog into proper alinement with the slots in the throat plate. he auxiliary feed bar is moved back and forth by a link connection to a bracket formed as a part of the feed rocker. This bracket has a segmental slot therein and the slot is so curved that when the stroke of the auxiliary bar is adjusted, the variations in the stroke all occur at the front end of the stroke of the auxiliary feed dog. By this arrangement of the slot in the bracket the space between the auxiliary feed dog when at the rear end of its stroke and the main feed dog may be kept constant. Both feed dogs are moved back and forth by the same feed rocker although one feed do may be given a greater extent of movement t an the other.

The means for oscillating the feed rocker is adjustably connected to the feed rocker and by shifting this connection the working position of the feed dogs may be shifted, and this shifting of the working position of the feed dogs is accomplished without in any way interfering with the differential movement imparted to the auxiliary feed dog.

eferring more in detail to the drawings, the invention is embodied in a sewing m chine consisting of a supporting bed which carries a work support Mounted on the work support 2 is a throat plate The machine includes the usual form of overhang arm 4 in which a needle bar 5 reciprocates,

' and in the present embodiment of the invention the needle bar 5 carries two needles 6 and 7. Cooperating with the needle 6 is a looper 8 and cooperating with the needle 7 is a looper 9. The loopers are mounted on separate carriers which are in turn pivotally mounted upon a loopcr support 10. The looper carriers are oscillated so as to move the loopers into and out of the needle thread loops by means of the link 11. The looper support 10 is oscillated so as to give the loopers a needle avoiding movement by means of an arm 12 which is fixed to the shaft carrying the looper support 10 and which cooperates with an eccentric on the main shaft 13.

The material is fed across the work support by a feeding mechanism which includes a main feed dog H having a plurality of feeding sections arranged. side by side but spaced from each other, and an auxiliary feed dog 15 likewise consisting of a series of feeding sections arranged side by side and spaced from each other. The material is held on the work supported by means of a presser foot 16 carried by a presser bar 17 of the usual construction.

The main feed dog 14 is carried by an angle bracket 18 (see Fig. 3). The shank of the feed dog is slotted so that screws 19 can be passed through these slots which are elongated and threaded into the bracket. There is a rib 20 on the shank of the feed dog which engages a similarly shaped groove in the bracket and this confines the adjustments of the main feed dog on the bracket to adirection at right angles to the l ne of feed or laterally of the main feed bar. This bracket 18 is secured to the main feed bar 21 by a screw The screw 22 passes through an elongated slot positioned so that the bracket 18 may be adjusted vertically on the main feed bar.

The main feed bar includes two spaced members 21a and 21?) and the main feed dog is secured to the member 21a. The members 210 and 21b of the feed bar are joined at the rear end by a yoke 21c and at the front ends by a Web or cross plate 21d. This connecting web 21d is indicated by broken lines in Fig. 5 as it is covered by the support to which the auxiliary feed dog is attached. A feed rockor 23 is attached to a shaft 24 by set screws 25, 25. This feed rocker has spaced sleeves 26, 26, and the yoke member 210 straddles one of the sleeves as shown in Fig. 10 of the drawings. As the feed rocker is oscillated it will move this main feed bar back and forth. Said feed rocker is oscillated by means of an arm 27. The arm 27 is connected by a link 28 to a crank pin 29 carried by a disk head 30 on the main actuating shaft 13. This arm 27 is L-shaped and carries at the opposite end from the connection to the link 28 a sleeve 31 which is fixed to the end of the shaft 24 carrying the feed rocker. That is, this sleeve is a split sleeve and is clamped to the shaft by means of a screw The main feed bar is secured to the sleeves 26,26 by a pin 33 and this pin extended beyond the feed rocker. At its end the pin passes through an enlarged slot 34, in the elbow of the arm 27 and a clamping nut 35 clamps the arm 27 against the side face of the feed rocker. By loosening this nut 35 and also loosening the screw 32, the angular pos tion of the arm 27 relative to the this adjustment.

feed" rocker can be varied. The enlarged opening at the elbow of the arm permits of This affords a means for shifting the working position of the parts actuated by the feed rocker.

The main feedbar is raised and lowered by an eccentric 36 on the main shaft 13. The main bar is provided with a bracket 37 which extends underneath this eccentric, and the construction whereby the feed bar is raised and lowered is of the usual form and further detailed description thereof is not thought necessary.

The auxiliary feed dog 15 is mounted on the free end of a shank 38. This shank 38 is disposed at one side. of the loopers as clearly shown in Fig. 2 of the drawings. The shank at its rear end is attached to a bracket 89 by a screw 40. The screw passes through an elongated vertical slot in the shank of the auxiliary feed dog and affords a means whereby said auxiliary feed dog may be raised and lowered. The supporting bracket 39 is attached to the auxiliary feed bar 41 by screws 42, 42. The bracket 39 has elongated slots extending lengthwise of the auxiliary feed bar and lying substantially in the line of feed. This screw and slot connection afiords a means whereby the auxiliary feed dog may be adjusted in the direction longitudinally of the feed bar; that is, toward and from the front end of the main feed bar. The auxil iary feed bar 41 is mounted on the main feed bar so that it may move freely back and forth thereon, and is raised and lowered with it. To accomplish this the auxiliary feed bar is provided with inclined faces at the side edges thereof and on the main feed bar are guide bars 43, 43, one attached to the member 2165 and the other attached to the member 21?). These guide bars also have inclined faces which engage the inclined faces on the auxiliary feed bar. The guide bars are held to the main feed bar by screws 44.

By these inclined faces and suitable removable shims, proper adjustment may be made for inaccuracies in machining, so that the auxiliary feed dog located at a considerable distance in front of the support for the auxiliary feed bar will be rigidly held in its back and forth movement. The auxiliary feed bar is provided with spaced perforated lugs 45 at the rear end thereof and a yoke link 46 is connected to a stud 47 passing through the lugs 45. This yoke link at its rear end straddles a bracket 48. The bracket 48 is formed integral with the sleeve 26 on the feed rocker. The bracket 48 is provided with a segmental slot 49, and a bolt 50 located in the yoke end of the link 46 passes through this slot.

The bolt 50 passes through a block 51 located in the slot and when the bolt is loosened this block can be adjusted in the slot and clamped in adjusted position by tightening the bolt. The yoke link 46, however, can

' swing freely on the bolt 50 as the feed rocker moves back and forth.

As clearly shown in Fig. 1a, a lining strip may be directed through a guide 52 carried by a bracket attached to the depending apron 53 of the work support 2. The threat plate is provided with a slot 54 which is located between the slots in the throat plate for the main feed dog and the slots for the auxiliary feed dog. The presser foot extends over this slot and is so positioned as to cooperate with both the auxiliary feed dog and the main feed dog, as clearly shown in Fig. 1a.

The supporting shank for the auxiliary feed dog extends around the side of the guide 52 and the auxiliary feed dog works in front of the guide.

From the above it will be apparent that a differential feeding mechanism wherein the auxiliary feed dog is so mounted on the auxiliary feed bar that it may be adjusted toward and from the needles and properly positioned for working in the'feed slots in front of the same, is provided. he auxiliary feed dog may also be raised and lowered so as to bring the auxiliary feed dog to a position above the throat plate at the desired time for feeding the material. There is also provided a support for the main feed dog which is located in rearof the needles, so that the main feed dog is shifted laterally or may be raised and lowered for properly positioning the feed dog relative to the feed slots and for taking care of any inaccuracies in the construction of the parts. Then again there has been provided means whereby the working position of both of the feed dogs may be shifted.

If for any reason the path of movement of the feed dog is not properly located relative to the feed slots or relative to the loopers, the working position of the feed dog may be shifted so as to move it rearwardly if desired. If then the auxiliary feed dog is not properly positioned it can be readily adjusted in a direction in the line of feed of the auxiliary feed bar, and thus both feed dogs properly positioned relative to the parts of the machine. The construction therefore lends itself to a proper positioning of the feed dogs for the machine, regardless of any slight inaccuracies in the construction or location of the parts.

t is obvious that minor changes in the details of construction may be made without departing from the spirit of the invention as set forth in the appended claims.

What is claimed as new is 1. A feeding mechanism for sewing machines including a feed rocker, a main feed bar pivotally connected thereto and having spaced parallel forwardly projecting members a yoke integrally connecting said members at the connection thereof to the feed rocker, an auxiliary feed bar mounted to slide freely on said main feed bar, plates secured to the main feed bar for holding said endof said arm for oscillatingthe feed rocker auxiliary feed bar thereon, the adjacent faces through said arm.

In-testimo y whereof, we aflix our signaof said plates and auxiliary feed bar being inclined whereby wear between the parts may be taken up, an auxiliary feed dog carried by said auxiliary feed bar, means carried by the feed rocker for moving said auxiliary feed bar and imparting a differential feedin movement thereto, and means for raising and lowering the feed bars.

2. A feeding mechanism for sewing machines including a feed rocker, a main feed bar having spaced parallel forwardly projecting members and an integral connecting yoke at the rear end of the feed bar, said feed rocker having a member extendingbetween the spaced members of the feed bar and ivotally connected thereto for moving said eed bar back and forth, a main feed dog carried by one of said members, an auxiliary feed bar mounted to slide freely on said parallel projecting members of said main feed bar, an auxiliary feed dog carried by said auxiliary feed bar, means connected to the member of the feed rocker to which the main feed bar is pivotally connected for imparting a differential feeding movement to said auxiliary feed bar, and means for raising and lowering said feed bars.

3. A feeding mechanism for sewing machines including a feed rocker a main food bar having spaced parallel forwardly projecting members and anintegral connecting yoke at the rear end of the feed bar, said feed rocker having a member extending between the spaced members of the feed bar and pivotally connected thereto for moving said feed bar back and forth, a main feed dog carried by one of said members, an auxiliary feed bar mounted to slide freely on said parallel projecting members of said main feed bar; an auxiliary feed dog carried by said auxiliary feed bar, means connected to the member of the feed rocker to which the main feed bar is pivotally connected for imparting a differential feeding IDOVOHIQIliJ to sai auxiliary feed bar means for raising and lowering said, feed bars, means for supporting said auxiliary feed dog on said auxiliary i feed bar so that it can be adjusted vertically and longitudinally of said bar and means whereby the working position of the feed dogs may be shifted.

4. A feeding mechanism for sewing machines. including a feed rocker, a feed bar pivoted to the feed rocker and movable back and forth by said feed rocker, means for raising and lowering the feed bar, a shaft on E which said rocker is mounted, fixed bearings for supporting said shaft, an angle arm mounted on said shaft and having an enlarged opening at the elbow thereof, clamping means extending through id opening for adjustably connecting said angle arm to the feed rocker, and means engaging the outer tures.

CHARLES s. THOMPSON. WILLIAM B. LONG. 

